Why does my TV switch from a channel I'm watching to a channel that is to be recorded at the time recording begins ? If I try to go back to the show I was watching I have to cancel the recording or stay and watch the show I'm RECORDING. It never did this before and what is the purpose of recording a show if you are forced to watch it.

Is there a setting to change to allow me to watch one show while recording another ?

Open your "guide" and select any current program and press the record button. Open the guide again and select a different current program and press the record button. Then open your List and there should show two programs recording.